Bitumen emulsion containing polyaluminum compounds

Abstract

The invention relates to an additive for a bitumen emulsion, which is a specific mixture of alkoxyiated compounds with low and high amounts of alkylene oxide units, in combination with a polyaluminum compound. Using this additive it is possible to prepare an aqueous slow-setting bitumen emulsion-aggregate mix suitable for cold paving of roads, parking places, sidewalks, and the like.

The invention claimed is: 
     
       1. An additive for a bitumen emulsion comprising
 i) a polyaluminum compound; 
 ii) an alkoxylated amine having the formula: 
 
       
         
           
           
               
               
           
         
       
       where R is a hydrocarbyl group having from 10 to 24 carbon atoms; n=0-3; each AO is independently ethyleneoxy or propyleneoxy, Y is a hydrocarbyl group having 1-24 carbon atoms, or a group (AO) x H; and the sum of all x in (I) is 0.5-10; and
 iii) an alkoxylated compound having the formula: 
 
       
         
           
           
               
               
           
         
       
       where R′ is a hydrocarbyl group from 8 to 24 carbon atoms; X is N, C(═O)O or O; s=0-3; p=0 or 1; provided that when X is N, then p is 1 and when X is C(═O)O or O, then p is 0; and Z is a hydrocarbyl group having 1-24 carbon atoms, or a group 
       
         
           
           
               
               
           
         
       
       where each AO independently is ethyleneoxy or propyleneoxy, and the sum of all y in (II) is from 12 to 200; or castor oil that has been alkoxylated 12 to 200 moles of ethylene oxide and/or propylene oxide per mole of castor oil (III). 
     
     
       2. The additive according to  claim 1 , wherein the sum of all x in formula (I) is from 0.5 to 5. 
     
     
       3. The additive according to  claim 1 , wherein the sum of all y in formula (II) is from 14 to 100. 
     
     
       4. The additive according to  claim 1 , wherein the AO in formula (I) is ethyleneoxy. 
     
     
       5. The additive according to  claim 1 , wherein the AO in formula (I) is propyleneoxy. 
     
     
       6. The additive according to  claim 1 , wherein at least 50% of the total number of AO-units in formula (II) or castor oil (III) is ethyleneoxy units. 
     
     
       7. The additive according to  claim 1 , wherein the AO in formula (II) is ethyleneoxy. 
     
     
       8. The additive according to  claim 1 , wherein the weight ratio of the alkoxylated amine to the alkoxylated compound is 1:25 to 4:1, and wherein the weight ratio of the polyaluminum compound to the sum of the alkoxylated amine and the alkoxylated compound is 1:30 to 1:2. 
     
     
       9. A bitumen-in-water emulsion comprising the additive according to  claim 1 , bitumen and water. 
     
     
       10. The bitumen emulsion according to  claim 9 , comprising
 50-75% (w/w) bitumen; 
 0.002-1.5% (w/w) of the polyaluminum compound; 
 0.05-3% (w/w) of the total of the alkoxylated amine and the alkoxylated compound; 
 0-20% (w/w) of other conventional components; and with the balance being water. 
 
     
     
       11. The bitumen emulsion according to  claim 9 , having a pH below 8. 
     
     
       12. The bitumen emulsion according to  claim 9 , wherein X in formula (II) is N and p is 1. 
     
     
       13. The bitumen emulsion according to  claim 9 , wherein Z is the group: 
       
         
           
           
               
               
           
         
       
     
     
       14. The bitumen emulsion according to  claim 9 , wherein X in formula (II) is O, p is 0 and s is 0. 
     
     
       15. A process for the manufacture of an aqueous bitumen-aggregate mix comprising the steps of:
 a) providing the bitumen emulsion according to  claim 9 ; and 
 b) mixing said emulsion with an aggregate. 
 
     
     
       16. An aqueous bitumen-aggregate mix comprising 2-40% by weight of the bitumen emulsion according to  claim 9 ; and
 60-98% by weight of an aggregate. 
 
     
     
       17. A method for paving a surface of a road, a sidewalk, a parking lot or an airport runway comprising the step of:
 spreading the bitumen-aggregate mix according to  claim 16  on the surface, or 
 spreading the bitumen emulsion according to  claim 9  on a surface at least partially covered by an aggregate. 
 
     
     
       18. The additive of  claim 1 , wherein the polyaluminum compound is polyaluminum chloride. 
     
     
       19. The bitumen emulsion of  claim 10 , wherein the polyaluminum compound is polyaluminum chloride.